In the example of a port-based surgery, a surgeon or robotic surgical system may perform a surgical procedure involving tumor resection in which the residual tumor remaining after is minimized, while also minimizing the trauma to the intact white and grey matter of the brain. In such procedures, trauma may occur, for example, due to contact with the access port, stress to the brain matter, unintentional impact with surgical devices, and/or accidental resection of healthy tissue.
Referring to FIG. 1, this diagram illustrates the insertion of an access port into a human brain, for providing access to internal brain tissue during a medical procedure, in accordance with the related art. The access port 12 is inserted into a human brain 10, providing access to internal brain tissue, wherein the access port 12 may include such instruments as catheters, surgical probes, or cylindrical ports, such as the NICO® BrainPath®. Surgical tools and instruments may then be inserted within the lumen of the access port in order to perform surgical, diagnostic, or therapeutic procedures, such as resection of tumors, as necessary.
Still referring to FIG. 1, access port surgery may be utilized in conjunction with catheters, deep brain stimulation (‘DBS’) needles, a biopsy procedure, and also to biopsies and/or catheters in other medical procedures performed on other parts of the body. In the example of a port-based surgery, a straight or linear access port 12 is typically guided down a sulci path of the brain. Surgical instruments would then be inserted down the access port 12. Optical tracking systems may be used with such medical procedures for tracking the position of a part of the instrument that is within line-of-site of the optical tracking camera. These optical tracking systems also require a reference to the patient to know where the instrument is relative to the target (e.g., a tumour) of the medical procedure.
In the field of medicine, imaging and image guidance are a significant component of clinical care. From diagnosis and monitoring of disease, to planning of the surgical approach, to guidance during procedures and follow-up after the procedure is complete, imaging and image guidance provides effective and multifaceted treatment approaches, for a variety of procedures, including surgery and radiation therapy. Targeted stem cell delivery, adaptive chemotherapy regimes, and radiation therapy are only a few examples of procedures utilizing imaging guidance in the medical field.
Advanced imaging modalities such as Magnetic Resonance Imaging (“MRI”) have led to improved rates and accuracy of detection, diagnosis and staging in several fields of medicine including neurology, where imaging of diseases such as brain cancer, stroke, Intra-Cerebral Hemorrhage, and neurodegenerative diseases, such as Parkinson's and Alzheimer's, are performed. As an imaging modality, MRI enables three-dimensional visualization of tissue with high contrast in soft tissue without the use of ionizing radiation. This modality is often used in conjunction with other modalities such as Ultrasound (“US”), Positron Emission Tomography (“PET”) and Computed X-ray Tomography (“CT”), by examining the same tissue using the different physical principals available with each modality. CT is often used to visualize boney structures and blood vessels when used in conjunction with an intra-venous agent such as an iodinated contrast agent. MRI may also be performed using a similar contrast agent, such as an intra-venous gadolinium-based contrast agent having pharmaco-kinetic properties that enable visualization of tumors and break-down of the blood brain barrier.
In neurosurgery, for example, brain tumors are typically excised through an open craniotomy approach guided by imaging. The data collected in these solutions typically consists of CT scans with an associated contrast agent, such as iodinated contrast agent, as well as MRI scans with an associated contrast agent, such as gadolinium contrast agent. Also, optical imaging is often used in the form of a microscope to differentiate the boundaries of the tumor from healthy tissue, known as the peripheral zone. Tracking of instruments relative to the patient and the associated imaging data is also often achieved by way of external hardware systems such as mechanical arms, or radiofrequency or optical tracking devices. As a set, these devices are commonly referred to as surgical navigation systems.
Three dimensional (3-D) sensor systems are increasingly being used in a wide array of applications, including medical procedures. These sensor systems determine the shape and/or features of an object positioned in a scene of the sensor system's view. In recent years, many methods have been proposed for implementing 3-D modeling systems that are capable of acquiring fast and accurate high resolution 3-D images of objects for various applications.
Triangulation based 3-D sensor systems and methods typically have one or more projectors as a light source for projecting onto a surface and one or more cameras at a defined, typically rectified relative position from the projector for imaging the lighted surface. The camera and the projector therefore have different optical paths, and the distance between them is referred to as the baseline. Through knowledge of the baseline distance as well as projection and imaging angles, known geometric/triangulation equations are utilized to determine distance to the imaged object. The main differences among the various triangulation methods known in the related art lie in the method of projection as well as the type of light projected, typically structured light, and in the process of image decoding to obtain three dimensional data.
A 3-D sensor system may be contemplated as a novel extension of a surgical navigation systems. One popular triangulation based 3-D sensor system is created by Mantis Vision®, which utilizes a single frame structured light active triangulation system to project infrared light patterns onto an environment. Other systems include Creaform 3D™ and Intel® RealSense™. To capture 3-D information, a projector overlays an infrared light pattern onto the scanning target. In an alternative system, Fuel3D Scanify®, the projector overlays visible light from multiple light sources. Thereafter, a digital camera and a depth sensor, synchronized with the projector, capture the scene with the light reflected by the object for at least the timeframe of one frame of the 3-D scan. This technique is applicable even in complete darkness, since the digital camera includes its own illumination; and, in bright environments, the quality of the resulting image depends on the hardware used.
During a related art medical procedure, navigation systems require a registration to transform between the physical position of the patient in the operating room and the volumetric image set, e.g., MRI/CT. Conventionally, this registration is done to the position of a reference tool, which is visible by the tracking system and stays fixed in position and orientation relative to the patient throughout the procedure. This registration is typically accomplished through correspondence touch points, e.g., either fiducial or anatomic points. Such an approach to registration has a number of disadvantages, including requiring fiducials to be placed before scans, requiring points to be identified, providing for a limited number of points, touch point collection is subject to user variability, and the physical stylus used for collecting the points can deform or deflect patient skin position.
Another conventional approach to collecting the touch points in the related art includes performing a surface tracing of the patient drawn as a line which is matched to the image set surface contour using either a stylus pointer or a laser pointer. Such an approach to registration has a number of disadvantages, including providing for a limited number of points, and the physical stylus can deform or deflect patient skin position. Yet another conventional approach to collecting the touch points includes using a mask, which requires a high level of operator training and is operator dependent. This approach also provides only a limited number of points.
Other common limitations of the foregoing conventional approaches to registration include a that a stylus needs to remain visible to the tracking system, which may not necessarily be possible depending on a patient's surgical position or may introduce surgical restrictions that need to be accounted in planning, and error accumulation where touch point or tracing collection is of low quality resulting in error propagation through subsequent steps of the registration. Further, using the conventional methods, if registration is lost, re-registration is difficult to be completed again during the surgical procedure.
In the related art, surgery, such as neurosurgery, for example, brain tumors are typically excised through an open craniotomy approach guided by imaging. Optical imaging is often used in the form of a microscope to differentiate the boundaries of the tumor from healthy tissue, known as the peripheral zone. Tracking of instruments relative to the patient and the associated imaging data is also often achieved by way of external hardware systems such as mechanical arms, radiofrequency, or optical tracking devices.
Some related art tracking systems use tracking markers disposed on a surgical instrument for facilitating navigation of such surgical instrument during surgery. Other related art tracking systems involve using tracking markers on a patient that are detectable during scanning or imaging. In such related art tracking systems, prior to treatment, a retroreflective, apertured, disk is applied to the patient precisely at a location defined by a “tattoo” wherein an aperture or hole is at a center of the disk is used to register the disk with the tattoo. The retroreflective, apertured, disk is detectable by a camera. In a related art tracking system, RFID tags are used on or in bandages for verifying or counting various items.
Other related art tracking solutions, such as Servo®, do not track the position and gaze of the surgeon during a surgical procedure. As a result, a probability exists that a trajectory of a robotic arm may intersect the position of the surgeon. A collision between the surgeon and the robotic arm and/or related instruments is an adverse event experienced in the related art and should be avoided in order to preserve the sterile field. A collision between the surgeon and the robotic arm and/or related instruments may further result in injury to a patient, a surgeon, or other medical personnel who are present. The probability that a collision will occur is increased in medical procedures with multiple clinical staff are disposed in, or cross, the optical camera's line of sight.
In yet other related art tracking systems, a tracking sphere is used in conjunction with a tracking camera to merely calculate the distance between tracked tools within the surgical workspace.
Accordingly, challenges experienced in the related art include surgical navigation systems that are unduly cumbersome, that provide inaccurate tracking of items, and that are unable to prevent accidental collisions between items and/or personnel in the surgical theatre. The movement of the robotic arm within the operating room may interfere with the medical procedure, the physicians, and the surgical team. Such interference may negatively impact the procedure or harm the patient. Therefore, a need exists for apparatuses and methods that facilitate restricting the movement of the robotic arm.